Prep: 1. Trim fat off beef roast. 2. Chop onion. Braise and shred beef: 1. Put roast in a 3-4 quart pan with 1/4 cup water. Cover and cook over medium heat, about 20 minutes. 2. Uncover and cook until meat is browned, turning, about 10 minutes. Lift out meat. 3. Add vinegar to pan, scrape brown bits at bottom. 4. Stir in broth, chili powder, and 1 teaspoon each of salt and cumin. 5. Return meat to pan, bring to boil, cover and simmer over medium heat until meat is easily pulled apart, about 1 1/2-2 hours. 6. Let meat cool, tear into shreds and mix with pan juices. Make chile mixture: 1. In a frying pan, combine oil, onion, chiles, and remaining 1 teaspoon cumin. Cook over medium heat, stirring occasionally, for 15 minutes. 2. Mix in flour, then blend in 1 cup sour cream and cook, stirring until simmering. Remove from heat and blend in remaining 1/2 teaspoon salt and 1 1/2 cups cheese. Cook tortillas: 1. Preheat oven to 375. 2. Heat 1/2 inch oil into a 7-8 inch frying pan. When hot, cook 1 tortilla at a time, 5 seconds on each side. Lay tortillas flat on paper towel to drain. Bake: 1. Spoon 1/3 cup chile mix and 1/4 cup shredded beef down center of each tortilla, roll to enclose. 2. Set enchiladas, seam side down in 9x13 inch baking sheet. Bake, uncovered for 15 minutes. 3. Sprinkle remaining 2 cups cheese evenly on top, return to oven and bake for 5 minutes more. Remove and serve with sour cream on the side.
These freeze super well! Let cool completely before freezing. To defrost just warm them in the microwave for 2-3 minutes. Bake covered if you prefer your enchiladas moist instead of crispy. Top with your favorite salsa! You can skip frying the tortillas to cut down on fat, instead just warm a stack of tortillas wrapped in a damp paper towel in the microwave, or fry each one for about 30 seconds per side in a dry skillet.